JPH0214382B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention improves the leafing properties of aluminum pigments, and does not particularly require undercoating or topcoating.
The present invention relates to a paint composition that can be finished in one coat. Leafing type aluminum pigment-containing epoxy resin paints are generally used for steel towers, bridges, tanks, etc.
It has been used in a wide range of applications, including vehicles. However, with conventional leafing-type epoxy resin paints containing aluminum pigments, it is not always possible to obtain a coating film with satisfactory leafing properties.
Therefore, it is often not possible to obtain a coating film with an aluminum feel,
Moreover, weather resistance etc. were also poor. Furthermore, since it is an epoxy resin paint, special care must be taken in treating the metal surface, and a high degree of surface treatment is usually required by sandblasting or other blasting treatment.
Therefore, in consideration of rust prevention properties, adhesion, etc., a method has been used in which an epoxy resin primer is usually applied and a leafing type epoxy resin paint containing aluminum pigment is applied thereon. In view of the above-mentioned current situation, the present invention has been developed to improve the leafing properties of aluminum pigments, to be able to coat objects with a wide range of metal substrate treatment levels, and to contain leafing-type aluminum pigments that can be used as both an undercoat and a topcoat. The object of the present invention is to provide an epoxy resin coating composition. For this purpose, in leafing type aluminum pigment-containing epoxy resin coating compositions, general formulas P-(S-CnH _2o+1 ) ₃ , P-(S-CnH _2o-1 ) ₃ , P-(S- A paint characterized by containing a phosphite trithioalcohol compound or a derivative thereof represented by CnH _2o-3 ) ₃ or P-(S-CnH _2o-5 ) ₃ (where n is an integer from 8 to 26) This is achieved by the composition. Conventionally, three-component paints have been used, consisting of a base component, a curing agent component, and an aluminum paste component, but with the coating composition of the present invention, a base component containing a phosphorous acid trithioalcohol compound or a derivative thereof is preliminarily added to the base component. The aluminum paste components can be mixed and stored, and a two-component paint form is also possible, resulting in good painting workability. Furthermore, the resulting coating film has good leafing properties, and a layer of aluminum flakes is formed on the surface of the coating film, resulting in a coating film with a good appearance and excellent weather resistance and rust prevention properties. Furthermore, as described above, since the paint according to the present invention has the functions of both an undercoat and a topcoat, it can be used as both an undercoat and a topcoat in one application, and the painting process can be shortened. The leafing-type aluminum pigment-containing epoxy resin coating composition of the present invention mainly comprises an epoxy resin, a curing agent, a leafing-type aluminum pigment, and a phosphite trithioalcohol compound or a derivative thereof. It is formulated with a solvent, anti-rust pigment, extender pigment, and various additives. As the epoxy resin, common epoxy resins for paints can be used. For example Epicron #840,
#860, #1050 (manufactured by Dainippon Ink and Chemicals), Epicote #828, #834, #1001 (manufactured by Ciel Chemical), Adekal Resin EP-4000, EP-4100,
Bisphenol A type epoxy resins such as EPX49-10, EPX49-52, EPX49-53 (manufactured by Asahi Denka Kogyo Co., Ltd.), DER#317, #331, #661 (manufactured by Dow Chemical Co., Ltd.); Adekal Resin EPX-4900 (manufactured by Asahi Denka Co., Ltd.) manufactured by Kogyosha),
Bisphenol F-type epoxy resins such as Epiron #830 (manufactured by Dainippon Ink and Chemicals) and EpoMitsuku R-140 (manufactured by Mitsui Petrochemical Industries, Ltd.); Typical examples include novolak type epoxy resins such as those manufactured by Nippon Ink Kagaku Kogyo Co., Ltd.). In particular, bisphenol F-type epoxy resin has a low viscosity, so the amount of solvent in the paint is reduced, making it possible to create a high non-volatile content paint, allowing for thick film coating, and also improving the leafing properties of aluminum pigments, making it ideal. be. As the curing agent, the usual curing agent for epoxy resins can be used. For example, aliphatic polyamines such as diethylenetriamine and triethylenetetramine, aromatic polyamines such as metaphenylenediamine and diaminodiphenylmethane, and polyamide resins can be used. The appropriate amount of the curing agent used is 0.5 to 1.0 equivalent relative to the epoxy equivalent of the epoxy resin. As the leafing type aluminum pigment, those commonly used in this type of paint can be used, but paste-like pigments whose surface has been treated with stearic acid or the like are particularly preferred. For example, commercially available products include Aluminum Top (manufactured by Tokai Kinzoku Co., Ltd.), Aluminum Paste Sap (manufactured by Showa Aluminum Powder Co., Ltd.), Alpaste (manufactured by Toyo Aluminum Co., Ltd.), Eterna Bright (manufactured by Silver Line Co., Ltd.), and Stapa (manufactured by Asahi Kasei Industries, Ltd.). Can be used. The appropriate amount of leafing type aluminum pigment to be used is usually 5 to 100 parts by weight per 100 parts by weight of the epoxy resin. In the present invention, the phosphite trithioalcohol compounds have the general formula P-(S-CnH _2o+1 ) ₃ , P-(S-CnH _2o-1 ) ₃ , P-(
Compounds represented by S-CnH _2o-3 ) ₃ , P-(S-CnH _2o-5 ) ₃ or mixtures thereof can be used. In addition, in the said general formula, n value is an integer of 8-26. Compounds with an n value of less than 8 are unstable and easily decomposed, and conversely, compounds with an n value of more than 26 have poor compatibility with other components, and both are not preferred. In addition, as a derivative of a phosphite trithioalcohol compound, one of the linear saturated thioalcohols or mono-, di- or tri-unsaturated thioalcohol groups in the above general formula can be substituted with phenol, thiophenol or a derivative thereof, such as an alkylphenol. Alternatively, those substituted with alkylthiophenol or the like can be used. These phosphite trithioalcohol compounds and their derivatives are known compounds per se and can be easily obtained. The amount of the phosphorous acid trithioalcohol compound or its derivative used is suitably 3 to 100 parts by weight, particularly preferably 5 to 25 parts by weight, per 100 parts by weight of the epoxy resin. If the amount of the phosphite trithioalcohol compound or its derivative used is less than the above range, the aforementioned effects cannot be expected, whereas if it is too much, the water resistance of the coating film will be extremely poor, which is not preferred. In the present invention, by blending the above-mentioned phosphite trithioalcohol compound or its derivative, the aluminum pigment can be made into a paint without losing its leafing properties even after long-term storage, and the aluminum pigment does not lose its leafing properties, which is required for conventional epoxy resin paints. There is no need for such severe surface treatment, and a coating film with excellent adhesion and yellowing resistance can be obtained. Suitable solvents to be used in the present invention include hydrocarbon solvents which are non-polar solvents such as toluene, xylene, benzene and naphtha. In addition,
When using polar solvents such as ketone solvents,
Because it reacts with aluminum paste, phosphite trithioalcohol compound or its derivatives,
For example, when these are mixed in advance with the base component and stored for a long period of time, the polar solvent needs to be mixed with the curing agent component. The appropriate amount of the solvent used is 10 to 70 parts by weight per 100 parts by weight of the epoxy resin. In addition, when using a phosphorous acid trithioalcohol compound or its derivative in a large amount within the above range, it is not necessarily necessary to add a solvent. Furthermore, in the present invention, as described above, antirust pigments and extender pigments can be used as necessary. The appropriate amount of these rust preventive pigments and extender pigments to be used is 200 parts by weight or less per 100 parts by weight of the epoxy resin. The present invention will be explained in detail below with reference to Examples. In the examples, "parts" and "%" are expressed on a weight basis. Example 1 25 parts of leafing type aluminum paste pigment (Aluminum Paste 53-119 [manufactured by Toyo Aluminum Co., Ltd.]), 10 parts of trithiotrilauryl phosphite and 5 parts of xylene were mixed in advance in a disper, and then Phenol F type epoxy resin (Epicron #830 [manufactured by Dainippon Ink and Chemicals])
50 parts of xylene, 5 parts of xylene, and 5 parts of anti-sagging agent were mixed and kneaded in a disper to form a main ingredient. Separately, modified aromatic polyamine (Sanmide M-
1400 (manufactured by Sanwa Chemical Industry Co., Ltd.)) 27 parts, calcium carbonate
35 parts of mica, 23 parts of mica, 5 parts of xylene, 5 parts of methyl isobutyl ketone, 4 parts of anti-sagging agent, and 1 part of suspending agent were kneaded in a disper to obtain a curing agent component. A paint was prepared by mixing the base agent component and the curing agent component at a ratio of (1:1). Example 2 A paint was prepared in the same manner as in Example 1, except that trithiotristearyl phosphite was used instead of trithiotrilauryl phosphite. Example 3 Leafing type aluminum paste pigment
After pre-kneading 20 parts of trithiotrilauryl phosphite, 10 parts of trithiotrilauryl phosphite, and 4 parts of xylene in a disper, 60 parts of bisphenol A type epoxy resin (Epicoat #828 [manufactured by Ciel Chemical Co., Ltd.]), 3 parts of xylene
1 part and 3 parts of anti-sagging agent were mixed and kneaded in a disper to obtain a main ingredient. Separately, 20 parts of polyamide amine (Tomide 255 [manufactured by Fuji Kasei Kogyo Co., Ltd.]), 35 parts of calcium carbonate, 10 parts of mica, 15 parts of xylene, 15 parts of methyl ethyl ketone.
1 part, 4 parts of anti-sag agent, and 1 part of suspending agent were kneaded in a disper to obtain a curing agent component. A paint was prepared by mixing the base agent component and the curing agent component at a ratio of (1:1). Example 4 A paint was prepared in the same manner as in Example 1 except that trithiotricapryl phosphite was used instead of trithiotrilauryl phosphite. Example 5 A paint was prepared in the same manner as in Example 1 except that trithiotrioleyl phosphite was used instead of trithiotrilauryl phosphite. Example 6 A paint was prepared in the same manner as in Example 1 except that trithiotrilinolenyl phosphite was used instead of trithiotrilauryl phosphite. Comparative Example 1 Example 1 except that 11 parts of a mixture of xylene and isobutanol was used instead of 10 parts of xylene as the solvent in the main component, and 10 parts of petroleum resin was used instead of 10 parts of trithiotrilauryl phosphite. A paint was prepared in the same manner as in Example 1. Comparative Example 2 A paint was prepared in the same manner as in Example 3, except that 17 parts of a mixture of xylene and isobutanol was used instead of 10 parts of trithiotrilauryl phosphite and 7 parts of xylene as the main ingredients. . Comparative Example 3 A paint was prepared in the same manner as in Example 1 except that trithiotricaproyl phosphite was used instead of trithiotrilauryl phosphite. Comparative Example 4 A paint was prepared in the same manner as in Example 1 except that trithiotrimerisyl phosphite was used instead of trithiotrilauryl phosphite. After storing the base ingredients prepared in Examples 1 to 6 and Comparative Examples 1 to 4 for a certain period of time, they were mixed with a curing agent component, and this paint was applied to a steel plate with a brush to a dry film thickness of 100 μm. After naturally drying for a week, the leafing property was visually judged. The results are shown in Table 1.

[Table] Good metallic feeling Almost no metallic feeling In addition, the paints prepared in Examples 1 to 6 and Comparative Examples 1 to 4 were applied to a sandblasted iron plate (SiS.Sa2・1/2) and a rusted iron plate (Type 2 Keren). Dry film thickness 100μ with a brush
After applying it and letting it dry naturally for a week,
Cross-cut and conducted salt spray test (1000 hours) and outdoor exposure test (1 year), and the results were used for the second test.
Shown in the table.

【table】

[Table] As is clear from Tables 1 and 2, the paint of the present invention has good leafing properties even after long-term storage, provides a coating film with a good metallic feel, and has excellent rust prevention properties. Ta. On the other hand, in the paints of Comparative Examples 1 to 4 that did not contain the phosphorous acid trithioalcohol compound used in the present invention, the paint film had a poor metallic feel after long-term storage, and the rust prevention properties were also poor. .

Claims (1)

[Claims] 1. A leafing type aluminum pigment-containing epoxy resin coating composition having the general formula P-(S-CnH _2o+1 ) ₃ , P-(S-CnH _2o-1 ) ₃ , P-( It is characterized by containing a phosphite trithioalcohol compound represented by S-CnH _2o-3 ) ₃ or P-(S-CnH _2o-5 ) ₃ (where n is an integer from 8 to 26) or a derivative thereof. Paint composition. 2. The coating composition according to claim 1, which contains 3 to 100 parts by weight of the trithiophosphorous acid compound or its derivative based on 100 parts by weight of the epoxy resin.